The discovery by Mighell & Roederer last year of flickering
red giants (FRGs) in the Ursa Minor dwarf spheroidal galaxy
has been confirmed through the analysis of four archival HST
WFPC2 observations in that galaxy. Many new FRG candidates
were found that exhibit low-amplitude brightness
fluctuations (at the few percent level) over timescales
ranging from minutes to hours. We describe the conservative
non-constancy statistical test used to detect these new
variable stars and present many detailed light curves which
have a much better time resolution than the observations
analyzed by Mighell & Roederer. M.L.F, was supported by the
NOAO/KPNO Research Experiences for Undergraduates (REU)
Program, which is funded by the National Science Foundation
through Scientific Program Order No. 3 (AST-0243875) of the
Cooperative Agreement No. AST-0132798 between the
Association of Universities for Research in Astronomy (AURA)
and the NSF. K.J.M was supported by a grant from the
National Aeronautics and Space Administration (NASA),
Interagency Order No. NNG05EB61I, which was awarded by the
Applied Information Systems Research (AISR) Program of
NASA's Science Mission Directorate.